a) Field of the Invention
The present invention relates to an apparatus for treating a photosensitive material and a method of adding water into the same apparatus, in which the concentration of a treating solution stored within a treating tank of the apparatus is held constant.
b) Description of the Prior Art
In an automatic developing machine, which forms part of the apparatus for treating the photosensitive material, a developing tank, bleaching tank, fixing tank, rinsing tank and a stabilizing tank are provided each storing a developing solution, bleaching solution, fixing solution, rinsing solution and a stabilizing solution (hereinafter generally referred to as a treating solution). The photosensitive material, which has been subjected to a stoving treatment, is sequentially immersed into each of the treating tanks and, after being developed, it is introduced into a drying unit, where it is dried prior to being withdrawn.
The treating solution deteriorates depending on the throughput of the photosensitive material. In order to recover the treating solution that has deteriorated, a solution is added into the treating tank and a corresponding amount is overflowingly delivered out of the treating tank as a waste solution. Such an amount of the treating solution to be replenished as it deteriorates can be readily calculated from the throughput of the photosensitive material. Meanwhile, referring to the evaporation loss of the treating solution, since only the water content within the treating solution is decreased, the concentration of the treating solution can be changed. Therefore, it is necessary to add an amount to of water corresponding to the evaporation loss independently of the replenished solution. However, since the evaporation loss varies with the changing of the surrounding environment, that is, the temperature or humidity or also depending on whether the apparatus is operating or shut down, it cannot uniquely be determined by calculation.
Therefore, it is proposed to immerse a concentration sensor, such as a hygrometer or the like, within the treating solution of each treating tank to add water based on a value sensed by the sensor. (See, for example, Japanese Patent Application Laid-Open No. 1-281446), in which change of the concentration of the treating solution can be recognized by the sensor so that an appropriate amount of water may be added into the treating tank.
Nevertheless, the operating reliability of the concentration sensor is low and it can often erroneously operate due to precipitation of the treating solution, which makes it impossible to add the appropriate amount of water. This can be also said of a level sensor such as a float or the like. In addition, the concentration sensor and level sensor are costly and lack practical usability. Thus, it is proposed to provide a monitoring tank independently of the actual treating tank and add water into the actual tank based on the evaporation loss for this tank (See Japanese Patent Application Laid-Open Nos. 1-254959 and 1-254960).
According to this, since data corresponding to the actual evaporation loss can be obtained, its reliability can be actually improved.
However, in the above-described water adding system, since the monitoring tank is necessary independently of the actual treating tank, the entire apparatus becomes bulky while the number of parts required for it is also increased. In addition, the management and maintenance becomes complicated in order to set a working condition similar to that of the actual treating tank.
In view of the above-described circumstances, it is an object of the present invention to achieve an apparatus for treating the photosensitive material and a method of adding water for use in the same, in which an equipment such as the monitoring tank for evaluating the evaporation loss may be eliminated from the apparatus itself and a reliable and appropriate amount of water to be added may be evaluated while its manageability and maintainability can also be improved.